Warning: NANOG-irrelevent flame about NSI contained herein. Hit "D" now.
There's really no reason any of us should be worried about NSI and the IAHC competing for domain name registries. But NSI is also pushing for control over the root domain (.) and if things get too heated up over that dispute we really could see a partition of the Internet at the DNS level.
This is not a concern. The DNS software vendors, and the root servers, all follow the IANA. When IANA says "go", we go. If NSI says "go somewhere else" then they become irrelevant, and they become a travesty, and their gravestone becomes another mile marker on the Internet's road to glory. This means "." moves to IANA-operated servers as soon as IANA says so. This means "COM" moves to IANA-approved servers as soon as IANA says so. This means NSI had best fire all of its lawyers and maybe its President/CEO. Internet B-I-G, NSI "little". The DNS namespace is a public trust, not a corporate asset. "Get over it."